1852.] DISAPPOINTMENTS. 249
the height of the river above the sea-level, at the point I reached. Nothing, however, can accurately determine this fact, but a series of barometer or " boiling-point " observations ; and to determine this height above the next great fall, and ascertain the true course and sources of this little-known but interesting and important river, would be an object worth the danger and expense of the voyage.
There is said to be a week's smooth water above this place, to the Jurupari caxoeira, which is higher than any below it ; and above this no other fall has been found, though traders have been ten or fifteen days up. They say the river still keeps as wide or wider than below, — that the water is as " white," or muddy, as that of the Solimoes, — that many trees, birds, and fish peculiar to the Solimoes are there found, — that the Indians have Spanish knives, ponchos, and coins, — and relate that, higher up, there are extensive " campos," with cattle, and men on horseback. All these interesting particulars seem to show that the river has its sources in the great plains which extend to the base of the Andes, somewhere near where the sources of the Guaviare are placed in most maps; but the latter river, from all the information I can obtain, is much smaller, and has a much shorter course. Having only a pocket surveying sextant, without any means of viewing two objects much differing in brilliancy, I endeavoured to obtain the latitude as accurately as I could, first by means of the zenith-distance at noon, obtained by a plumb-line and image of the sun, formed by a lens of about fifteen inches focus ; and afterwards, by the meridian altitude of a star, obtained on a calm night, by reflection in a cuya of water. I took much care to ensure an accurate result, and have every reason to believe that the mean of the two observations will not be more than two or three minutes from the truth.
My expectations of finding rare and handsome birds here were quite disappointed. My hunter and Senhor Nicolau killed a few umbrella-birds of the Rio Negro species ; but of the white bird such contradictory statements were given, — many knowing nothing whatever about it, others saying that it was sometimes, but very rarely seen, — that I am inclined to think it is a mere white variety, such as occurs at times with our blackbirds and starlings at home, and as are sometimes found among the curassow-birds and agoutis. Another bird,
